I forgot the title of this on manga that want to revisit ... but I forgot what it’s called!

The story follows the woman/girl who has reincarnated into the body of the girl’s favorite character in a novel. This character happens to be a villainess. The villainess is the princess of the country, is in line for the throne, and has an incurable disease that will eventually kill her. Anyway, the reincarnated girl takes the place of the evil princess and she totally fan girl’s all over the place -very funny bit. After much fan girling, the reincarnated girl decides that she is going to save the rest of the characters she likes from the path of destruction that the novel’s main character couple leaves behind in their path to HEA.

Did I imagine this story line or can someone tell me the title of it? I am 99% certain that this storyline is from a manga and not a novel.

Ps. It is not “Miss Not So Sidekick”

The title is:

When the Villainess Loves

"The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein

Omg! That’s the one. Thank you so much for helping.